Background and Objective: Drug trafficking is one of the most important security and economic challenges in the northwestern border regions of the country. Purely law-enforcement and reactive approaches have not led to a sustainable reduction of this phenomenon. Therefore, the present study aims to identify the functions of good border governance in preventing drug trafficking in the northwestern border areas.

Methodology: The study is applied in purpose and qualitative in nature. Data were collected through semi-structured interviews with 16 experts, specialists, and university professors familiar with the subject. Purposive sampling was used, and theoretical saturation was achieved. Data analysis was conducted using thematic analysis at three levels: basic, organizing, and global themes. The validity and reliability of the interviews were confirmed using expert opinions.

Findings: The findings showed that the functions of good border governance in preventing drug trafficking consist of four global themes: 1) security-control (smart border control, physical surveillance, cross-border and inter-institutional cooperation); 2) development-economic (development of sustainable livelihoods, job creation, support for local products, and transforming the border into a commercial bridge); 3) social-participatory (social empowerment, public participation, education, cultural development, and social investment); and 4) legal-judicial (deterrent law and punishment, transparency, continuous oversight, and anti-corruption).

Conclusion: Good border governance cannot be merely security-oriented or merely economic-oriented; rather, the simultaneous integration of smart control, economic development, social participation, and the rule of law is essential for sustainable prevention of drug trafficking. There is a significant gap between the current situation, in which the security-reactive approach dominates, and the desired situation of integrated and participatory governance. Achieving this requires political will, redesigning institutional structures, allocating resources, and empowering local communities.